What do scientists think of evolution as a theory?

Watch the video that I will show you in class and answer the following questions:
  • Does theory becomes a fact? Theory explains a fact
  • Why is Evolution an important theory in Biology?
  • What is the key element of hypothesis or theory?
  • So what does a theory do?

But Evolution is JUST a theory

  • What is a theory in a scientific sense?
  • Do you need to see to “believe” in a theory?
  • What can scientists rely on theory for?
  • What are inferences based on?


Theory explains facts
-> a framework to ask question to explain phenomenon
-> leads to predictions
-> explains laws and facts
-> Evolution explains biodiversity
-> theories put together observations, laws and hypothesis
-> may not be something that can proven with what we see but helps to explain what we observe eg. gravitational theory (we don't see gravity)
-Darwin came up with theory through laws, observations and evidence at hand

What is evolution?

  • Evolution is a process that results in heritable changes in a population spread over many generations.
  • Biological evolution is change in the properties of populations of organisms that transcend the lifetime of a single individual.
  • Biological evolution refers to populations and not to individuals
  • Changes must be passed on to the next generation- heritable
  • Therefore it can also be defined as: 
any change in the frequency of alleles within a gene pool from one generation to the next

allele-genes that stands for same type of trait e.g. alleles for straight and wavy hair

Macroconcept: Change occurs with time

Where did the idea come from-> influence from many people
Voyage on Beagle
Alfred Russel Wallace was a naturalist wokring mostly in the Malay Archipelago-> read essay on the principle of population by Malthus -> "flashed upon me the idea of sruvival of the fittest"->Wallace had studied the distribution of animal species and concluded that both a selection and an evolution had to have taken place.